Metering pump



Aug. 1, 1967 G. ALBAUT 3,333,543 y METERING PUMP Filed Dec. 18, 1964 3Sheets-Sheet l [NVE/VIVI? Gusta/1 ALBAl/T G. ALBA UT METER ING PUMP Aug.l1

Filed Dec. 18, 1964 5 Sheets-Sheet 3 Gasto);

United States Patent O 3,333,543 METERING PUMP Gaston Albaut, Paris,France, assignor to Societe responsabilite limitee dite Sonal,Argenteuil, Seine-et- Oise, France, a corporation of France Filed Dec.18, 1964, Ser. No. 419,496 14 Claims. (Cl. 10S-38) The inventionconcerns a metering pump having a variable and adjustablemicro-delivery, capable of delivering a strictly regulated ow of luid,for example from 0.1 cm.3 to 100 cm.3 per hour and even longer. It canbe used in all kinds of iields: physics, chemistry, physico-chemicalwork, biology, medicine land even nuclear energy. It may be constitutedin such a manner that the delivered uid of various types come in contactonly with speciiic inaterials which can be sterilised lif necessary;these materials may have a mineral, vegetable and animal, metallic orplastic base.

The pump according to the invention has a certain number of featureswhich may be iused separately or in combination.

The driving device for the pump piston is constituted by a synchronousmotor provided with a speed reduction box and the output shaft of thereduction box carries an eccentric on which rotates aroller connected toa positive drive for the pump piston.

The eccentric which makes it possible to vary the travel of the piston,i.e., to regulate and obtain the desired delivery, is mounted on avariable-position fork, being for this purpose mounted pivotably and theposition of the pivot being geometrically chosen to automaticallycorrect an advance or delay at the opening of the delivery valve inaccordance with the amount of the delivery rate and more exactly tocorrect the instant the piston has reached the top in View of theinstant the intake valve opens.

The admission and delivery valves are situated in two separate chamberswhich are in communication through suitable ducts, and said valves arecontrolled =by rockers operated by a slide provided with a push member,the said slide carrying two diametrally opposed rollers rolling on a camsolidly iixed to the driving shaft, which ensures the alternating linearmovements necessary for delivery.

The portion of each rocker incorporated in the charnbers of the suctionor intake and delivery valves is completely insulated from the outsideby spherical sealing joints having a constant volume.

The end of the intake or suction valve is connected to the end of thesleeve of the rocker by a exible ring which ensures the opening andclosing of the valve in a positive manner, whilst the delivery valve mayrest on the corresponding rocker Iby its own weight; in this case, anelastic tongue whose free end continually bears on the delivery valveexerts thereon a suicient force to prevent any irregular displacement ofthe valve under the iniiuence of the pressure of the delivered fluid. Y

The movements of the rockers causing the opening and closing of thevalve are eiected by a push member actuated lby the aforesaid slide withinterposition of springs, and so that the closing of the suction and theopening of the delivery are successively effected without thepossibility of communication between the two chambers.

In order to compensate for compression and expansion yforces at thesprings of the rockers operating the valves and to keep the lrotationalspeed of the motor strictly constant despite the periodic variations inthe resistant torque, the slide acting on the push member of the rockerscomprises two opposed ramps of such .a conliguration that a roller,mounted on a pivoting lever on a disc driven by 3,333,543 Patented Aug.1, 1'967 ICC the driving shaft, in following the said ramps, compressesor relaxes a coil spring connected, on the one hand, to the disc and onthe other hand, to the end of the pivoting lever, so that it ybecomespossible to brake the speed ofthe motor when the latter tends to rotatemore quickly, and to speed up the motor when it tends to rotate lessquickly.

Other features will become apparent from the following description whichrefers to the accompanying drawings wherein:

FIGURE l is a longitudinal sectional view of the pump assembly taken onI-I of FIGURE 2;

FIGURE 2 is a cross section of the same assembly on II-II of FIGURE 1;

FIGURE 3 is a cross section of the same assembly on III- Ill of FIGURE1, looking on to the opposite face;

FIGURE 4 is a View showing the regulating mechanism and FIGURE 5 is aside view of the same mechamsm;

FIGURE 6 is a partial view of the slide controlling the rockers with theregulating ramps.

Referring now to the iigures, there is mounted on a base 1 by means of acradle 2 a casing 3 closed at one side with a vertical counter-plate 4and supporting at the other side a casing 5 with cover 6 foraccommodating a synchronous motor 7. This motor is provided with areduction gear of any desired type capable of reducing the speed of themotor for example lfrom 1,500 revolutions per minute to 2 revolutionsper minute. Fixed on the counter-plate 4 by any suitable means are adistributor unit 8 and the pump body proper 10 whose chamber is 'linedwith a cylindrical liner 9 which may be made of glass, plastic material,stainless steel and, ygenerally speaking, of any sterilisableincorrodible material. The liner 9 is held in its housing -by a nut 25.The driving shaft 11 at the output side of the reduction box issupported by a bearing 14 lodged in the counter-plate 4; it drives aneccentric 12 constituted by a sleeve of variable and regulatableeccentricity as will -be indicated hereinafter, and on its externalsurface there rolls at one time, a roller 13 connected by a link 24 tothe pump piston 15 which may be made of glass or any other material, bymeans of a coupling device 16, 17; at another time a roller 13a, the xedspacing of the two rollers being such that they simultaneously rest onthe sleeve 12 at the top and bottom neutral points of the piston 15. Thefluid pumped in and delivered by the displacement of the piston 15within the pump chamber passes through the ducts 18 shown in full linesand 19 shown in dot-dash lines since the latter are situated above thesection plane.

The sleeve 12 forming an eccentric is mounted in a fork 20 mountedpivota-bly on a pin 22. The two rollers 13, 13a, carried 'by the fork,successively roll on the sleeve. The fork may be optionally positioneddepending on the desired travel, i.e., depending on the desired deliveryto be obtained; the adjustment is obtained by two opposed screws 21which are accessible from the exterior through a cylindrical orifice 23in the casing 3 (FIG. 2).

In FIGURES l and 2, the eccentric sleeve 12 has been illustrated in itsposition centered on the axis 11 of the motor 7. In this position, thepiston obviously remains motionless. The possible eccentricity `is e(FIG. 2). Considering the rotation-direction r, when the sleeve 12 isgiven a certain eccentricity e towards the bottom, the roller 13a,resting on the sleeve, operates for 180 to lower the piston 15 towardsthe bottom, and then, immediately the roller 13 contacts the sleeve 12and produces a reverse movement of the piston.

As it may `be seen in FIGURE 2, the pin 22 of the fork 20 which carriesthe rollers 13 and 13a in its median position is substantially placed ona perpendicular axis to the piston, passing through the axis of theroller 13. Whenl the eccentricity e is changed for the adjustment of the3 lluid delivery (FIG. 2), the fork 20 rotates: the roller 13substantially remains at the same contact point on the sleeve 12, due tothe position of the pin 22, whi-le the lroller 13a displaces its contactpoint with the sleeve 12 in the direction of rotation r, that is thedelay direction.

It is known that in the case of sma-ll fluid deliveries, thedisplacement of the pumped in liquid is produced with a delay in view ofthe displacement of the piston. This possibly results from the fact thatdissolved gases are always included in the liquid and that they slowlyescape, under the eiect of a decrease of pressure due to the pumpingaction, therefore before the liquid starts to move. This delay decreasesand is subsequently nulliiied with the increase of the liquid delivery,because the escape of the gases does not have the time to be dissolvedcompletely.

The shape of the cam 42 is set to produce a constant delay at thebeginning of the suction action, that is in view of the passage of thepiston at its upper neutral point for the little deliveries. Theincrease of the delivery by the variation of the eccentricity e resultsin a progressive delay of the passage of the piston at the upper neutralpoint, due to the corresponding rotation of the fork as it has beenexplained above; it results that the initial delay of the opening of thepumping through the rocker 30 is progressively reduced by the movementof the fork in case of an increase in the delivery. The determination ofthis reduction which obviously depends on the distance of the pin 22 ofthe fork to the axis of the roller 13a, is empirically determinedaccording to the liquids used.

According to FIGURE 3, the distributor casing 8 comprises two housingsfor the suction and delivery valves 38 and 47, which are mobile in therings 48 held in place by Iplugs 34 and 36 ensuring a tight seal. Theplug 36 carries the suction pipe connection 37 and the plug 34 carriesthe delivery pipe connection 35. The fol-lowing arrangements aim atpreventing any perturbation in the smooth operation of the pump in thevariations of the volumes located at the upper and lower ends. Thehousings of the valves 38 and 47 open respectively into theperpendicular chambers 49 for suction and 50 for delivery. The rockers30 and 31 have one end movable in these chambers and are centrallysupported by sealed spherical bearings 32, which enables a free angulardisplacement of the rockers about the said bearings without any volumevariation. The end of each rocker situated within the chambers 49 and 50acts on the valves 3S and 47 and may be covered with a sleeve 33 oftexible plastic material which is sterilisable. The end of the rocker 30is connected to the valve 38 by a flexible ring 58 tted on to the saidvalve which is provided with a suitable collar. Between the end of thedelivery valve 47 and the end of the rocker 31 there is interposed anelastic tongue 53 which is parallel to the rocker, which exerts on theend of the valve a slight pressure opposing pumping movements of thevalve in its housing. The chambers in which the rockers are displaceableare perfectly duid-tight.

Displacement of the rockers is effected by a at slide 26 carrying two.rollers 41 which roll on a double cam 42 driven by a driving shaft 11;the slide, guided by a ixed stud 44 sliding in a notch 5I, therefore hasa linear alternating movement in the sense of the arrows f1 and f2. Theslide terminates at its upper end in a push member 27 accommodated in acasing 8 and iixed to a spherical sliding bearing 28 situated betweenthe two rockers 30, 31. Compressed springs 29'and 52 are lodged in thecasing, which constantly apply the rockers against the bearing and areopposed in equilibrium as illustrated in FIG. 3. In its displacement,the slide 26 entrains the push memlber 27 and the bearing 28. When,progressively, the rocker 31 displaces itself in the direction of theopening of the delivery valve 47, -by compressing the spring 52; theforce of the spring 29 of the suction valve previously compressed isexerted on the rocker 30 in the direction of closing the suction valve38. In the other part of the movement of the slide, the spring 52 whichhad been compressed exerts its force on the rocker 31 which acts in thesense of closing the valve 47 and the bearing 28 acting on the rocker 30in the sense of opening the suction valve compresses the spring 29.

It is obvious that the alternating compression and relaxation of thesprings are not without intluence on the running state of the motor,which in order to ensure exact-ly the desired delivery rate, shouldrotate at a constant running speed. For this purpose, the apparatuscompnses a regulator capable of providing a remedy for operating shocks.The mechanism involved in regulation consists in interposing between thedriving shaft and the slide actuating the rockers, but subjected to thecompression and relaxation of the springs of the rockers 29 and 52, aspring which can `be compressed when the motor tends to rotate morequickly and relaxed in the opposite case. For this purpose, the slide 26comprises at its centre an aperture 40 and opposed ramps 43. Parallel tothe slide 26 there is mounted on the driving shaft (FIGS. 3 to 6) a disc45 on which is pivotably mounted a lever 56 carrying at its end a roller54 capable of travelling along the ramps 43. A coil spring 57 is fixedon the one hand to the disc 45 at 4S, and on the other hand to the lever56, so that any relative movement given to the lever by the roller 54following the ramps will tend to compress or relax the spring 57. Anymovement tending to compress the spring tends to have a braking effecton the disc, that is to say to slow down the motor, and vice versa.Therefore, it is sufficient to provide a configuration for the ramps 43to regulate the speed of the motor in an effective manner.

Thus constituted, the pump according to the invention is self-primingand its operation automatically ensures the elimination of all gaseousbubbles from the time of stating. The delivery of the uid delivered isso regular that the level of the fluid delivered in a tube shows a veryregular height without any agitation, contrary toV all devices used atthe present time wherein the suction and delivery periods haverepercussions on the column of fluid, the level of which is not at al1stable.

It is advantageous for bringing the pump rapidly into service to beginwith a maximum delivery and to progressively reduce the delivery to thedesired value; elimination of gaseousbubbles and t-he like is theneiected under the best possible conditions.

What I claim is:

1. A liquid pump having a smooth and adjustable delivery, comprising achamber containing a cylinder, a pump piston, and circulation channelsfor the liquid, a synchronous motor, means for actuating the piston by apositive control through the motor, suction and delivery valves, locatedin the chamber, a rocker control for each of the said valves passingthrough the said cham-ber, a sealed joint for supporting each rockerthrough the charnber, and control means for the rockers through the saidsynchronous motor.

2. A pump according to claim 1, wherein each rocker is a bar, the meansto control the rockers comprising a rod substantially perpendicular tothe rockers, a spherical piece solidly fixed to the -rod for supportingthe rockers, two springs, one for each rocker, compressed in oppositedirection, a cam carried -by the output shaft of the said motor, guidingmeans for the said rod in translation according to its axis, at leastone roller carried at the free end of said rod and bearing on the saidcam.

3. A pump according to claim 2, wherein the control means for therockers by the said motor 'include the said cam carried by the saidoutput shaft of the motor, a slide solidly fixed to the said control rodof the rockers, with a I linear guiding slot, two rollers carried by theslide and lresting on both sides ofthe said cam.

4. A pump according to claim 3 comprising a compensating means for thevariations of the efforts supported by the motor due to the alternativecompression of the springs resting on the rockers, comprising a camcarried 'by the said slide, a disc solidly xed to the output shaft ofthe motor and perpendicular to the latter, a lever actuated on the saiddisc, a roller carried at one end of the said lever and resting on thesaid cam, a spring under tension between the other end of the said leverand a point on the said disc.

5. A pump according to claim 1, wherein the positive control comprisesan eccentric constituted by a cylindrical sleeve carried by an outputshaft of the motor, adjusting means for the eccentricity of the saideccentric, two rollers having a -xed spacing corresponding to thesimultaneous contact point across a diameter of the sleeve of theeccentric, a fork supporting the said rollers, a xed pivoting shaft forthe said fork, parallel to the driving shaft of the motor, andsubstantially located on an axis perpendicular to the piston passingthrough the median position of one of the rollers, a link articulated ona roller and on the pump piston.

6. A pump according to claim 1, wherein the suction and delivery valvesand the part of the rockers located within the said cham-ber arecompletely located in the volume of the chamber containing the liquidcirculation.

7. A pump according to claim 6, wherein the rockers are connected to thevalves, the upper valve being connected by its own Weight, and the lowervalve being connected by a connecting piece made of exible materialbetween the ends of the rocker and the valve.

8. A metering pump having a smooth adjustable delivery ow comprising:

(a) a pump body including a cylinder and a pump piston,

(b) a synchronous motor,

(c) positive driving means connecting said motor to the said pumppiston,

(d) suction and delivery valves mounted in a distributor unit,

(e) duct means to provide the circulation of a liquid from the said pumplbody to the said valves,

(f) rocker means for actuating each valve,

(g) a pusher member connected to the rocker means for actuatingsuccessively each valve through the positive driving means,

whereby a Iregular and smooth liquid delivery is obtained during theactuation of the valves.

9. A pump as recited in claim 8, wherein the rocker means comprise twobars, actuated Iby the pusher member at approximately 90 to the bars, aspherical bearing solidly mounted on the pusher member between the twobars, each bar being biassed against the said bearing by a spring, a cammember mounted on an output shaft of said motor, the said pusher memberbeing actuated by the rotation of the cam member.

10. A pump as recited in claim 9, comprising a slide iixed to the pushermember, a linear guiding slot in said slide, two rollers mounted on saidslide and resting on the cam so as to follow the contour of the cam.

1i. A pump as recited in claim 1i), comprising compensation means forthe variations of the speed of the motor due to the compressions of thesprings.

12. A pump as recited in claim 11, wherein the compensation meanscomprise a second cam connected to the slide, a disc solidly `mountedperpendicular to the output shaft of the motor, a lever pivoted on saiddisc, a roller mounted at one end of said lever and biassed in thedirection of the said second cam whereby the said second cam is computedto damper any variation in speed of the motor.

13. A pump as recited in claim 8, wherein the positive driving meanscomprise an eccentric constituted by a cylindrical sleeve axiallymounted on the output shaft of the motor, means for throwing the saidsleeve off center, two rollers having a iixed spacing corresponding tothe diameter of the sleeve and rolling on the said sleeve, a fork forsupporting the said rollers, the said fork pivoting on an axle parallelto the axis of the shaft of the motor, and substantially perpendicularto the axis of the piston passing through the median position of one ofthe rollers, and a pivoting link between one of the rollers and the pumppiston.

14. A pump as recited in claim S, wherein the suction and deliveryvalves and a part of the rockers are located within a liquid circulationchamber, the upper va-lve `being connected to one rocker by its ownweight and the lower valve being connected to the other rocker at theirextremities by a connecting piece made of flexible material.

Reierences Cited UNITED STATES PATENTS DONLEY J. STOCKING, PrimaryExaminer. LAURENCE V. EFNER, Examiner. W. I. KRAUSS, Assistant Examiner.

8. A METERING PUMP HAVING A SMOOTH ADJUSTABLE DELIVERY FLOW COMPRISING:(A) A PUMP BODY INCLUDING A CYLINDER AND A PUMP PISTON, (B) ASYNCHRONOUS MOTOR, (C) POSITIVE DRIVING MEANS CONNECTING SAID MOTOR TOTHE SAID PUMP PISTON, (D) SUCTION AND DELIVERY VALVES MOUNTED IN ADISTRIBUTOR UNIT, (E) DUCT MEANS TO PROVIDE THE CIRCULATION OF A LIQUIDFROM THE SAID PUMP BODY TO THE SAID VALVES, (F) ROCKER MEANS FORACTUATING EACH VALVE, (G) A PUSHER MEMBER CONNECTED TO THE ROCKER MEANSFOR ACTUATING SUCCESSIVELY EACH VALVE THROUGH THE POSITIVE DRIVINGMEANS, WHEREBY A REGULAR AND SMOOTH LIQUID DELIVERY IS OBTAINED DURINGTHE ACTUATION OF THE VALVES.